It sounds like you're trying to plug in multiple monitors across different GPUs...that's a recipe for disaster. Plug all monitors into a single GPU. If you've got a 4070, you're already more than capable of 4+ monitors on that card, what are you doing exactly?
Only good reason for doing what you're doing is for something like GPU passthrough in proxmox where you're passing your DGPU through to a virtual machine.
The integrated GPU in the 7900 is exceptionally weak, and generally only good for "home office" use.